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B D Spiess

Publications and source records attributed to B D Spiess.

72 records · Page 4Linked to original sources
PubMed1988

Effects of high-dose fentanyl on fluid and vasopressor requirements after cardiac surgery.

The effects of two different anesthetic techniques on postoperative cardiopulmonary events, fluid and vasopressor requirements, and overall intensive care unit (ICU) course were studied in patients undergoing elective myocardial revascularization (CABG) (N = 20) or single cardiac valve replacement (N = 20). Patients were randomized to receive either high-dose fentanyl (F, 75 microg/kg followed by 0.3 microg/kg/min) or diazepam-ketamine (0.8 mg/kg D and 2 mg/kg K followed by 0.07 mg/kg/h D and 1 mg/kg/h K). No significant differences in preoperative demographics, prebypass hemodynamics, ischemic crossclamp, or total cardiopulmonary bypass times were noted. Patients receiving F had lower systemic arterial pressures and vascular resistances and required more vasopressors during the first 12 hours postoperatively. They also had a more positive cumulative fluid balance at 24 and 48 hours postoperatively, despite a higher incidence of postoperative diuretic use in CABG patients receiving F. Rectal temperature was significantly higher at four and eight hours postoperatively in F patients. Time until arousal and length of ICU stay were significantly greater with F, although duration of intubation did not differ between anesthetic techniques. Although the data does not provide an explanation for these differences, it indicates that these two techniques produce quite different physiologic responses in the postoperative period following cardiac surgery. In summary, it was found that F for cardiac surgery was accompanied by increased postoperative fluid and vasopressor requirements with increased Qsp/Qt and longer ICU stays compared to diazepam and ketamine. This study suggests that some anesthetic techniques may provide less complicated and less costly postoperative courses than others, with the same outcome after cardiac surgery. Information on the postoperative effects of long-acting anesthetic agents is sparse and more studies of these effects and their mechanisms are necessary because they may affect patient management after cardiac surgery.

Aged↗
PubMed1988

The incidence of venous air embolism during total hip arthroplasty.

Venous air embolism has been reported to occur during total hip arthroplasty. The incidence of venous air embolism, however, has not been previously studied in a large series using Doppler ultrasound and mass spectrometry. Seventy patients undergoing total hip arthroplasty were monitored for venous air embolism with precordial Doppler ultrasound, central venous catheter, end-tidal N2 and CO2 (mass spectrometry), and arterial blood gases (ABG). Changes in the monitored variables consistent with venous air embolism were noted in 57% by Doppler ultrasound, 9% by mass spectrometry, 4% by central venous catheter and 3% of the cases by ABG. A total of 77 Doppler ultrasound events were detected in 40 of the 70 patients studied. Hemodynamic changes consisting of either hypotension, defined as a greater than or equal to 20% decrease in mean arterial pressure (MAP), or cardiac dysrhythmia occurred during 43% of these events. The Doppler ultrasound was the only monitor that detected all cases of venous air embolism with concomitant hemodynamic changes. Air was aspirated from the central venous catheter during 10% of the detections of venous air embolism by Doppler ultrasound. Venous air embolism in total hip arthroplasty is a common event and may be responsible for hemodynamic changes previously ascribed to the use of methylmethacrylate cement. Routine monitoring with Doppler ultrasound appears warranted. The routine use of central venous catheterization may also be warranted.

Blood Gas Monitoring, Transcutaneous↗
PubMed1988

Coagulation monitoring in the surgical intensive care unit.

This article reviews the basic coagulation mechanism and how it has routinely been monitored. It points out some common perceptual pitfalls clinicians encounter when thinking about these tests. New horizons in perioperative hypocoagulability monitoring techniques are presented. Methods of evaluating and charting therapeutic progress for venous and arterial thrombotic diseases are also reviewed.

Blood Coagulation↗
PubMed1988

Effects of continuous arteriovenous hemofiltration on cardiopulmonary abnormalities during anesthesia for orthotopic liver transplantation.

Orthotopic liver transplantation (OLT) often involves large blood loss and replacement, as well as administration of large amounts of blood products to correct coagulation defects. Renal free water excretion is often impaired in end-stage liver disease and not responsive to routine diuretic therapy, predisposing these patients to accumulation of extravascular lung water. The effects of the intraoperative use of continuous arteriovenous hemofiltration (CAVH) on cardiopulmonary and oxygen transport variables were studied in ten patients during and 24 hours after OLT. CAVH prevented increases in pulmonary shunt fraction while decreasing PEEP and FIO2 requirements. Pulmonary compliance was significantly higher after operation in patients receiving CAVH. Before surgical dissection, hemodynamic effects of CAVH were minimal. Postoperatively, patients having CAVH had lower cardiac filling pressures and more normal systemic vascular resistance than did patients not having CAVH. These data suggest that CAVH may be a useful intraoperative technique for patients with impaired renal function undergoing liver transplantation.

Adolescent↗
PubMed1988

Treatment of decompression sickness with a perfluorocarbon emulsion (FC-43).

Decompression sickness is caused by the production of tissue and blood stream inert gas bubbles. Perfluorocarbon emulsions (PFC) have enhanced O2 and N2 solubilities as well as a small particle size as properties. The effects of treatment with a PFC (FC-43) and 100% oxygen on decompression sickness were investigated in 24 Sprague-Dawley rats compressed to 6.8 ATA and rapidly decompressed. Survival in animals receiving PFC and 100% oxygen was significantly longer (P = 0.01) than in those receiving a 6% hetastarch (H) treatment. The PFC survivors at 24 h did not demonstrate any neurologic deficits, whereas the 1 H animal surviving at 24 h was ataxic and not eating. Those animals who died most often did so within minutes after decompression, suggesting a hemodynamic demise. We conclude that PFC treatment when coupled with 100% oxygen breathing provides both hemodynamic and neurologic protection from decompression sickness.

Animals↗
PubMed1987

Thromboelastography as an indicator of post-cardiopulmonary bypass coagulopathies.

Postoperative hemorrhage in patients undergoing open-heart surgery is a major cause of morbidity and mortality. Monitoring of coagulation in these patients has routinely involved the activated clotting time. Thromboelastography is currently used as a monitor of coagulation during liver transplantation. The thromboelastogram, by providing information on the interaction of all the coagulation precursors, gives more clinically useful information on coagulation than that available from the coagulation profile or the activated clotting time alone. This study was done to assess the usefulness of thromboelastography in open-heart surgery. Thirty-eight patients (29 undergoing coronary artery bypass grafting and 9 undergoing valve replacement) were studied with activated clotting time, thromboelastography, and coagulation profiles during three periods: before bypass, during bypass, and after protamine administration. Thromboelastography was a significantly better predictor (87% accuracy) of postoperative hemorrhage and need for reoperation than was the activated clotting time (30%) or coagulation profile (51%). Thromboelastography is easy to use and provides diagnostic data within 30 minutes of blood sampling.

Blood Coagulation Disorders↗
PubMed1987

Protection from coronary air embolism by a perfluorocarbon emulsion (FC-43).

The protective effects of a perfluorocarbon emulsion (FC-43) against the physiological sequelae of selective coronary air embolism (CAE) were examined in dogs. Animals were randomly assigned to two groups: group 1 received 20 mL/kg of 6% hetastarch in 0.9 normal saline solution with 280 mg/L of CaCl2; group 2 received 20 mL/kg of FC-43 (Oxypherol, Alpha Therapeutic Corp, Los Angeles). Infusion time for both groups was 30 minutes. Following a ten-minute stabilization period, a 0.02-mL/kg bolus of air was injected into the left anterior descending coronary artery distal to the first branch. Surface and epicardial ECGs, systemic BP, pulmonary artery pressure, central venous pressure, left ventricular pressure, left ventricular end-diastolic pressure (LVEDP), dP/dtmax, and Vmax were recorded continuously. Cardiac output (by thermodilution technique), myocardial creatine phosphokinase levels and the lactic acid concentration were measured. The study revealed a significantly lower systemic mean arterial pressure (MAP), LVEDP, left ventricular stroke work index (LVSWI), and right ventricular stroke work index (RVSWI) in the group receiving the FC-43 prior to receiving CAE. Possible causes of the differences are a species-specific direct vasodilating effect of FC-43 or histamine release. Following CAE, myocardial function as measured by dP/dtmax, Vmax, and MAP was lower in group 1 during the first five minutes following CAE. ECG tracings showed all of the ten group 1 dogs had ST-T changes (greater than 2 mm), and six of the ten had ventricular dysrhythmias or conduction defects. Only one of the group 2 dogs showed ST-T wave changes (P = .0006, Fisher's exact test), and none had dysrhythmias (P = .005, Fisher's exact test).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Effects of nitrous oxide on coronary perfusion after coronary air embolism.

Coronary air embolism (CAE) can occur after heart surgery whenever air is present in the left heart or proximal aorta. When CAE occurs, its sequelae can range from electrocardiographic changes of ischemia to severe myocardial dysfunction and cardiac arrest. Since N2O has been shown to have detrimental effects in the presence of coronary obstructions, as well as the tendency to enlarge air emboli, the authors tested the hypotheses that N2O would enhance the deleterious effects of CAE, and that discontinuing N2O at the time of CAE would minimize those effects. The effects of ventilation with and without N2O on the cardiac insult due to left anterior descending CAE (0.02 ml.kg-1) were studied in 27 swine. Global cardiovascular changes that occurred after CAE included decreases in cardiac output, systemic arterial and coronary perfusion pressure, and LV dP/dt, as well as increases in LVEDP. These parameters returned towards baseline over time when N2O was discontinued at the time of CAE. Maintenance of N2O in the inspired gas after CAE occurred was uniformly fatal within 2-4 min in this model. Regional myocardial ischemia was significantly greater in animals receiving N2O, as documented by: 1) a greater incidence of elevations of epicardial ST-segments exceeding 3 mm from baseline in embolized and non-embolized coronary artery distributions, 2) a greater incidence of dysrhythmias (greater than 6 PVCs.min-1), 3) longer duration of depression of coronary blood flow, 4) longer duration of post-ischemic coronary hyperemia, and 5) larger decreases with less recovery over time of regional myocardial lactate extraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Effects of progressive blood loss on coagulation as measured by thrombelastography.

The effects of progressive blood loss on coagulation were studied in 87 adults (age 23-66 yr) undergoing a variety of operations under general anesthesia. None had preoperative alterations in coagulation or liver function and none were receiving anticoagulant or antiplatelet medication. Whole blood coagulation status was quantitated using thrombelastography (TEG). Blood samples for TEG were obtained 5 min before and 15 min after induction of anesthesia, after each increment of blood loss (EBL) equalling 5% of estimated blood volume (EBV), at the end of surgery, and 2 hr post-operatively. Patients with EBL exceeding 0.15 EBV were given packed red cells and crystalloid solution. Patients with EBL less than 0.15 EBV received only crystalloid. Thrombelastography analysis showed a trend toward increased coagulability with progressive blood loss. Two of four patients with 80% loss of EBV maintained normal to enhanced coagulation status, although the other two developed clinical and thrombelastographic evidence of coagulopathy. Thrombelastography allowed rapid intraoperative diagnosis and specific treatment of loss of platelet activity in the latter two patients. We conclude that during moderate to massive blood loss, use of supplemental fresh frozen plasma and/or platelets should be reserved for patients with documented defects in coagulation. Thrombelastography is useful for the detection and management of coagulation defects associated with intraoperative blood loss.

Adult↗
PubMed1986

Protection from venous air embolism with fluorocarbon emulsion FC-43.

Intraoperative venous air embolism (VAE) occurs frequently in some surgical settings and may cause devastating hemodynamic consequences. Perfluorocarbon emulsions have been investigated as artificial oxygen carrying medias. They also have the properties of enhanced nitrogen solubility and a small particle size. FC-43 (Oxypherol, Alpha Therapeutic Corp., Los Angeles, California) was compared to three other volume expanders in 91 New Zealand White laboratory rabbits exposed to continuous VAE. The animals were anesthetized and ventilated by one of four modalities. They then received one of the volume expanders at 20 cc/kg over 30 min. After a 10-min stabilization period, a constant femoral venous air infusion (0.25 cc/kg/min) was begun and continued until death. Time until death, total volume of air infused, femoral arterial pressure, central venous pressure, and ECG (Lead II) were recorded. Death was defined as the cessation of pulsatile blood pressure. Arterial and central venous gases were analyzed pre and post volume expansion and at intervals of every 5 min after the beginning of the femoral air infusion. Results showed a significant prolongation of life for the animals receiving FC-43 at 10 and 20 cc/kg as a volume expander and mechanically ventilated with 100% oxygen as compared to all other groups (P less than 0.05). PaO2 and PvO2 were consistently higher in the group receiving FC-43 as a volume expander. Central venous pressure was lower during air embolism in the FC-43 group. The mechanism for the enhanced survivability of rabbits pretreated with FC-43 volume expansion exposed to VAE is under further investigation.

Animals↗
PubMed1986

Cardiorespiratory effects of venous air embolism in dogs receiving a perfluorocarbon emulsion.

The cardiorespiratory effects of a nonlethal venous air embolism were studied in dogs in the presence of a perfluorocarbon emulsion (PFE). Prior to embolization, five dogs received 20 cc/kg of hydroxyethyl starch (6% HES) and five received PFE oxypherol (20% FC-43). Determinations of mean systemic arterial pressure (MAP), pulmonary artery pressure (PAP), left ventricular pressure (LVP), first and second derivatives of LVP with respect to time (dP/dt and Vmax), cardiac index (CI), stroke index, left and right ventricular stroke work index (LVSWI and RVSWI), PaCO2, PaO2, and venous admixture (Qs/Qt) were made before and then 1, 5, 10, and 30 minutes after placement of the venous air emboli (0.75 cc/kg/min for 5 minutes). After emboli were introduced, PaO2, MAP, LVSWI, dP/dt, Vmax, and CI decreased; the average decrease during the first 5 minutes was significantly less in the PFE group. Following introduction of venous air emboli, PAP, PaCO2, RVSWI, and Qs/Qt increased less in the PFE group than in the HES group, with statistical significance achieved at various times during the first 10 minutes after embolism. All parameters returned toward baseline values by 30 minutes in both groups. This study indicates that FC-43, when administered before venous air embolism, helps to attenuate some of the detrimental cardiorespiratory effects of the embolism.

Animals↗
PubMedDate not supplied

Protection from cerebral air emboli with perfluorocarbons in rabbits.

Cerebral air emboli have been implicated in the transient neurological deficits seen in patients after cardiovascular surgery. Since perfluorocarbon emulsions such as FC-43 have greater solubilities for gases compared to plasma, it was decided to investigate their potential in providing protection against transient ischemia produced by such emboli. Forty rabbits were divided into three groups of ten, twenty, and ten. They were anesthetized with acepromazine and ketamine and were given an infusion of either hetastarch or FC-43, 10 ml/kg i.v. In Group I, which received a bolus air injection into the internal carotid artery, survival rates were: 2/5 for the hetastarch group and 5/5 for the FC-43 group (p less than .05). In Group 2, which received an air infusion until the EEG was flat bilaterally, 3/10 hetastarch-treated rabbits survived while 10/10 FC-43-treated rabbits survived for 24 hours (p = .035). In Group 3, analysis of blood viscosity and osmolality over a four hour period following either hetastarch or FC-43 infusion resulted in no significant differences between the two treatments but a significant decrease in both variables after 30 minutes which returned to baseline values at 60 minutes. The results of the study demonstrate a protective effect from cerebral air emboli delivered into the internal carotid artery as either a bolus or slow infusion in rabbits pretreated with a perfluorocarbon emulsion in terms of survivability and recovery from transient neurological deficits.

Animals↗